[https://nvbugs/5449218][fix] Fix KvCacheConfig error in test_perf (#6937)

Signed-off-by: peaceh <[email protected]>

Author: peaceh-nv

tests/integration/defs/perf/pytorch_model_config.py

@@ -17,8 +17,6 @@
 Model pytorch yaml config for trtllm-bench perf tests
 """
 
-from tensorrt_llm.llmapi import KvCacheConfig
-
 
 def recursive_update(d, u):
     for k, v in u.items():
@@ -202,9 +200,10 @@ def get_model_yaml_config(model_label: str,
             lora_config['lora_config']['max_lora_rank'] = 320
         base_config.update(lora_config)
 
-    kv_cache_config = base_config.get('kv_cache_config', KvCacheConfig())
+    kv_cache_config = base_config.get('kv_cache_config', {})
     if 'kv_cache_dtype' in base_config:
-        kv_cache_config.dtype = base_config.pop('kv_cache_dtype', 'auto')
+        kv_cache_dtype = base_config.pop('kv_cache_dtype', 'auto')
+        kv_cache_config['dtype'] = kv_cache_dtype
         base_config.update({'kv_cache_config': kv_cache_config})
 
     return base_config